                1. Filed of the Invention        
The present invention relates to a pressfit terminal that can connect a connection terminal such as a connector to a printed wiring board without soldering and to a connection structure.
2. Description of the Related Art
In any of the conventional substrates such as a printed wiring board fitted with an electronic circuit loaded with electronic parts, connection terminals are used for electrical connection with any external source. There are many cases in which a plurality of connection terminals are assembled so as to form a connector. There are also many cases in which, not only electrical connection, but substantial mechanical strength is also required. For this reason, there are many instances in which connection terminals are used via insertion into through holes formed in a substrate instead of being loaded in the substrate surface.
In order to obtain stable electrical connection and mechanical strength, a connection terminal inserted into a through hole is often soldered. Mostly, the soldering process is practiced using eutectic crystal consisting of about 40% lead (Pb) and about 60% tin (Sn). However, as a result of recent tendencies to avoid the use of lead, specifically, due to the lead-free inclination, when connection terminals are soldered, it is required to use a lead-free brazing material. Nevertheless, generally, the lead-free brazing material requires temperature higher than that in a case of soldering with a eutectic crystal for connecting terminals. When the temperature is raised due to the soldering of the connection terminals, electronic parts forming an electronic circuit on a printed wiring board may incur an adverse influence. To solve this problem, attention has been focused on a pressfit terminal enabling highly reliable electrical connection without soldering (see JP-U-Hei.2-119514 and JP-B-2911043).
In a case where a substrate is thick due to multilayer structure, if only a single press contact portion between a pressfit terminal and an inner wall face portion of a through hole is provided in the thickness direction of the substrate, there is a fear that the substrate may bend due to the bending moment. To prevent this phenomenon, JP-U-Hei.2-119514 discloses a structure including plural press contact portions in the thickness direction of the substrate. JP-B-2911043 discloses a structure in which a body portion near a tip end of a pressfit terminal is divided into two parts and the two parts are deviated and can be contact with an inner wall face portion of a through hole.